STRASMORE/EXPLORE 2,170 QUERIES

What changed between consecutive top-of-book messages (AAPL, 10:00 to 10:30 a.m. ET, June 16, 2026)

Answered against 22 years of US equities and 12 years of US options data and published with the query that produced it. This result is stored as of 2026-08-12, from MBO vs MBP Order Book Data Explained.

as of ranking 4×3read in context →
What changed between consecutive top-of-book messages (AAPL, 10:00 to 10:30 a.m. ET, June 16, 2026) — 4 rows by 3 columns, computed from US exchange, SIP and OPRA data.
message_typemessage_countshare_pct
best bid price changed2017717.6
size joined at the best bid1999617.4
size left the best bid1373012
bid untouched, ask side updated6088753
Rows × columns
4 × 3
Computed
Completeness
No missing values
Source
US exchange, SIP and OPRA market data
Licence
Strasmore terms · free, no signup
Formats
JSON · CSV · the SQL below

What each column holds

Column definitions for What changed between consecutive top-of-book messages (AAPL, 10:00 to 10:30 a.m. ET, June 16, 2026), derived from the stored result.
ColumnTypeRangeNotes
message_type text 4 distinct values
message_count number 13,730 to 60,887 count
share_pct number 12 to 53 percent

Computed from Strasmore's warehouse of US exchange, SIP and OPRA market data. Equity prices are delayed; options greeks and implied volatility are end-of-day. This result is stored, not recomputed on load — it is exactly the numbers that were returned on , and the query below is what returned them.

the exact SQL behind every number
WITH
    ordered AS
    (
        SELECT
            row_number() OVER (ORDER BY sip_timestamp, sequence_number) AS msg_index,
            bid_price,
            bid_size,
            lagInFrame(bid_price) OVER (ORDER BY sip_timestamp, sequence_number) AS prev_bid_price,
            lagInFrame(bid_size)  OVER (ORDER BY sip_timestamp, sequence_number) AS prev_bid_size
        FROM global_markets.cache_stocks_quotes
        WHERE ticker = 'AAPL'
          AND sip_timestamp >= '2026-06-16 14:00:00'
          AND sip_timestamp <  '2026-06-16 14:30:00'
          AND bid_price > 0
    ),
    classified AS
    (
        SELECT multiIf(
            bid_price != prev_bid_price, 'best bid price changed',
            bid_size  >  prev_bid_size,  'size joined at the best bid',
            bid_size  <  prev_bid_size,  'size left the best bid',
            'bid untouched, ask side updated') AS message_type
        FROM ordered
        WHERE msg_index > 1
    )
SELECT
    message_type,
    count()                                        AS message_count,
    round(100 * count() / sum(count()) OVER (), 1) AS share_pct
FROM classified
GROUP BY message_type
ORDER BY indexOf(['best bid price changed', 'size joined at the best bid', 'size left the best bid', 'bid untouched, ask side updated'], message_type)

Run your own version of this

The same 22 years of US equities and 12 years of options data are queryable in SQL or plain English. A free account runs 100 queries a day and takes no card.

More from this analysisMBO vs MBP Order Book Data Explained
Trade size mix in the same window (AAPL, 10:00 to 10:30 a.m. ET, June 16, 2026) ranking 5×4 Top-of-book messages against prints, 10:00 to 10:30 a.m. ET, June 16, 2026 ranking 5×4 Average quoted spread and time at a one cent spread, midday June 10 2026 ranking 6×3 How AAPL prints break down by trade size, June 10 2026 ranking 5×3 The best bid and the price levels it visited, AAPL, 15 minute buckets series 24×3 Top of book messages against prints on the tape, AAPL, June 10 2026 series 8×4 See all 2,170 queries →